Adriana Lima has been a Victoria's Secret model since 2000. She's talking about her stage fright before the the lingerie giant's annual fashion show, which she will appear in for the eleventh time on Wednesday.

Behind the scenes at the Victoria's Secret headquarters, the designers, stylists and producers have gathered for one of the final fittings before the event, which draws eight million viewers.

"I feel the music, I feel the clothes, I feel the people and that's how I react. I don't plan in advance," Lima adds.

Surrounded by rails of bras and knickers, there are bags full of sequins, beads and Swarovski crystals pinned to mood boards. A half-finished feathered corset sits on a table amongst rolls of ribbons, hats and costume jewellery. Tailors' dummies with eight-foot high wings stand nearby. Behind a white curtain, it takes a team of eight to help Lima into one of her costumes: a purple bustier, lace gloves and shimmering black feather wings, attached by leather straps.

The wings are made by a costume designer called "Killer" (real name Marian Jean Hose). Todd Thomas, the head designer for the show, is in deep conversation with Sophie Neophitou - the British fashion editor who's styling the show this year - by a board covered in photographs of each of the 68 looks. There will be 38 sets of wings.

"The models look athletic, strong and healthy; for me, that's inspiring," says Neophitou. "We are creating a moment, a fantasy."

Says Thomas: "Using Adriana Lima as an example, this is a woman who is promoting strength and health, and a dedication to one's self. She is the example of what the woman in this show is: she is strong and empowered. She is doing these things out of self respect, rather than external desires to be acknowledged."

The Victoria's Secret team start working in earnest in April every year. They reference films, books and couture collections, then start sketching, drawing up mood boards and thinking out story lines. From 10 ideas presented to the head honchos at Victoria's Secret, six were selected.

"I started out with the idea that I wanted it to feel really luxurious, as if each section is a little couture vignette," says Neophitou. "Each piece has to be the most beautiful piece it can possibly be. I work on couture shows as well - but this is a whole different moment of total fantasy."

Those vignettes this year are themed "Super Angels", "Passion Play", "Angels Aquatic", "I Put A Spell On You" and "Club Pink".

"The closest comparison I can make is to an Elie Saab couture show [which Neophitou also styles] because there's been a lot of handwork. That's what I equate it to. In this world you are not bogged down by the costs of a fabric, or what the mark-up's going to be for a garment to be reproduced a million times."

For each look, Neophitou took items of underwear that are actually available in the stores. She says there is a misconception that everything worn at the show is specially made and has little relation to what can be bought on the high street.

"You are dealing with actual product. That purple outfit [the one Lima can be seen modelling in the photographs above] - a basque, suspenders, stockings - that is actual product available here in the catalogue," she says turning to the appropriate page. "The product here is the unsung hero. We then build a story around a piece. People don't understand how much attention to detail goes into it."

And what of that rumoured $10million budget for the show? "I can tell you that it's beyond most productions that I have worked on, it is the fantasy job," says Thomas. "There is a definitive amount. At the beginning you think, 'Oh I can make this happen', then you start doing and making and engaging people, and you want more once you get that taste of luxury. It's hard to edit that as you complete the process: it is an exercise in maintaining a budget, even though it's a hefty one."

Fashion show or costume theatre, the Victoria's Secret event is in a genre all of its own, a marketing dream which has paid off handsomely (and a vehicle that's made its models both rich and famous).

"I think the show is a little bit of both," says Thomas. "All good fashion is theatre."